The present invention pertains to the field of window construction. More particularly, the present invention is a product-by-process, namely, a one-piece window component, such as a frame or sash, made by the process of injecting a second volume of molten polymer into a mold having a first volume, the second volume of thermoplastic resin being less than the first volume, the method further employing the step of injecting high pressure fluid (gas or liquid) to force the polymer into the recesses and to create an insulative core in said window component.
Within the current state of the window art, window components, such as frames and sashes, are manufactured by extruding a continuous length of material, cutting angled (mitered) corners to the desired dimensions of the window and connecting the cut pieces through welding or using fasteners. Cutting and welding require follow-up cleaning operations to produce a clean part. So many operations, each requiring handling by one or more workmen, significantly increase the cost of production. In addition, there are structural integrity issues: the strength of a frame made of multiple parts is weaker than one that of one-piece construction. Any torquing of the frame can produce loosening of the joints or fasteners. The extruding step does not permit any variation in the outline of the structural member so that any shaping, to provide clearance for hinge hardware, for example, involves an additional secondary operation adding still further cost. All attachment hardware must be mounted using fasteners which, again, adds an expensive secondary operation.
The product-by-process of the present invention remedies these short comings of the prior art. The one-piece, injection molded window component of the present invention (both the window frame and the window sash) has enhanced strength characteristics, including resistance to the effects of torque. Injection molding permits three-dimensional blending of geometries. The clearance recesses for support hinge hardware, as well as the pivot hardware itself, may be directly molded into the window profile. Likewise, the pivot post for the window latch may be molded onto the inner face of the window sash. Significant labor savings is realized eliminating costs associated with mitering and other cutting, welding or screwing, and clean-up operations following the cutting and welding steps. The processing characteristics for an injection molded material are somewhat less stringent than those for extrusion. Accordingly, the material may be chosen for its strength, appearance and wearability rather than being limited by its extrudability. The material of choice is a filled polypropylene (fillers include glass, talc, and calcium carbonate). A volume of this molten thermoplastic polymer generally equal to about 75% of the volume of the mold is injected into the mold through a gate provided therefor. High pressure fluid (nitrogen or water) is injected through a pin orifice at pressures in the range of between 300 and 2000 psi to push the volume of molten plastic outwardly into contact with the walls of the mold and into all the recesses therein. While plastic is a more effective insulator than some materials used for extruded windows (aluminum, for example), an insulative cavity will be formed at the core of the mold by the pressurized fluid. This encapsulated air pocket enhances the insulative characteristics of the window and, in addition, reduces the amount of plastic it takes to construct the window component, thereby reducing material costs.
A first window, a casement window, resulting from this product-by-process, has a number of unique features. The casement window includes a one-piece window frame including a first hollow body housing an insulative air pocket; a first integrally molded pocket on each side of the window frame for receiving support hinge hardware; a one-piece window sash including a second hollow body housing an insulative air pocket, a second integrally molded pocket on each side of the sash operating with the first integrally molded pockets on said window frame to house the support hinge hardware; the support hinge hardware attached to both the window frame and the window sash in the first and second integrally molded pockets, respectively.
The casement window of the present invention preferably additionally includes flexible installation flanges which are trimmed to a size slightly larger than a window opening to receive the casement window and are folded back in the opening during installation. A recess on an external periphery of said window frame is provided for receiving a lip seal and lip seal retainer. The window frame includes a first integrally molded pivot hinge member that mates with a second integrally molded pivot hinge member on the sash to permit pivoting movement of the window sash in the window frame.
The casement window sash has a glazing bead recess integrally molded in an external periphery of said window sash. A latch mounted on the integrally molded pivot post, includes a latch handle and a latching arm which engages a latch retainer on the window frame to secure the window sash in a closed position. A screen securement groove is formed in an outwardly protruding surface of the seal retainer.
A second window design made according to the product-by-process of the present invention is a picture window frame that includes a first outer frame portion comprising a first one-piece, injection molded element with a window pane receiving pocket and having a hollow insulative core; a second inner frame portion comprising a second one-piece, injection molded element with a window pane receiving pocket and having a hollow insulative core; means to secure the second inner frame member to the first outer frame member sandwiching the window pane and retaining the window pane there between.
Another feature of the present invention comprises a window pane fashioned to resemble glass block. A first molded rectangular acrylic panel is formed into a first plurality of apparently separate portions with intervening mortar-like seams, each individual apparently separate portion being slightly outwardly convex and having a light-diffusing rippling therein. A second molded rectangular acrylic panel is formed into a second plurality of apparently separate portions with intervening mortar-like seams, each individual apparently separate portion being slightly outwardly convex. Means to secure said first and second panels is provided such that the slightly outwardly convex portions extend outwardly and the mortar-like seams extend inwardly into a juxtaposed position.
Various other features, advantages and characteristics will become apparent after a reading of the following specification.